1. Field of the Invention
The present invention relates generally to apparatus for deceleration of projectiles, and containment of those projectiles and their fragments and particulate resulting therefrom. More particularly, it concerns apparatus for guiding a projectile into a chamber where successive armor plates contain the projectile within a confined area. The bullets, fragments and resulting particulate matter are then collected and confined for disposal or recycling.
2. Background Art and Background of the Invention
It is understood that when a bullet or other projectile hits a surface it has a propensity to deform. This is particularly true for lead bullets hitting hard surfaces, as is often the case in target practice with small arms. This deformation is frequently in the form of fragmentation of the projectile into smaller components, even to the point of generation of airborne particulate matter. The terms "bullet" and "projectile" are used broadly herein. They mean the original body as placed in motion, as well as any fragments or particulate matter formed upon primary and subsequent impacts of the projectile and its fragments, as well portions of other projectiles which may be set in motion on impact with the projectile or its fragments. The terms "bullet" and "projectile" are used interchangeably.
Target practice is an activity pursued by many to enhance shooting skills, as criteria of employment, or for sport. It is customary in target practice to provide a means of stopping projectiles after they have traveled through or by a target, and before their potential to harm persons or damage property is concluded. This is traditionally accomplished by such means as providing adequate proximity between the target and persons and property, constructing a barrier such as an earthen berm, or strategically locating a solid fixture such as a wall or a metal plate. Proximity solutions involve massive facilities in light of modern weapons with long and powerful trajectories. This wastes valuable land resources and requires time consuming travel to less populated areas.
Merely providing an earthen or other barrier may stop the bulk of the projectiles, but has no effect on the indiscriminate distribution of lead, the primary material used for projectiles, into the environment. Lead is a heavy metal environmental contaminant increasingly implicated as a health risk to humans and animals.
Barriers are subject to wear and eventual failure. Simple barriers and fixtures may stop a projectile, but allow lead fragments or particulate to escape into the environment. Barriers without containment deflect bullets which may retain enough velocity to harm bystanders, the shooter, or property. These barriers still require a significant proximity solution due to deflected projectiles. Barriers without containment loose the bullets to the surrounding environment and disallow recycling the matter into new projectiles or other usable goods.
The term "plate" is used herein in its broadest sense as a planar sheet of material capable of stopping or deflecting a projectile and its fragments. It will be understood by those of ordinary skill in the art, that selection of plate material is made in consideration of the nature and velocity of the various projectiles to be stopped and contained. For high velocity, high mass, jacketed bullets, the material of choice may be hardened steel plate or the equivalent; for projectiles from small air guns, a material with less impact resistance may be chosen. Similarly, plates intended to take primary, direct impacts will necessarily be stronger than those to take secondary or tertiary impacts from more acute angles.
Recent emphasis has been placed on stopping and containing projectiles by the use of bullet traps and stops, and containment systems employing a variety of configurations intended to stop a projectile and contain the resultant products. For example in U.S. Pat. No. 4,821,620, to Cartee et al. (1989), it is described to provide a screen of rubber-like material followed by a deflector plate. The bullet is said to travel through the screen and be stopped by the plate, bullets and fragments then are said to fall down between the two components to a collector. This has the particular disadvantages of wear of the rubber-like material, increasingly diminished margins of containment with wear, the likelihood of escape of projectiles back through the screen with enough energy to cause harm to persons or property, and the inability to significantly contain airborne particulate matter from the projectiles.
Others including Bravaglio in U.S. Pat. No. 4,512,585 (1985), and Coburn U.S. Pat. No. 5,070,763 (1991), describe containment chambers with curved portions said to reduce the velocity of projectiles as they travel along the curved surface. However, curved plate is costly to manufacture, transport, store, and assemble. It is very bulky as compared to flat plate. Virtually all of the energy from projectiles over time in these devices is absorbed in a very limited area of the curved or otherwise complex structure in these chambers, necessitating expensive repair, reconstruction, or replacement. Bullet stops with curved portions are said to have the advantage of maintaining the integrity of the projectile, thereby preventing the escape of fragments and particulate matter from the normal pathway. In practice, high velocity projectiles fragment on impact, explode from the forces of angular velocity upon rotation, or melt.
Another problem yet unsolved by the prior art is containment of fine fragments and particulate matter created on impact without the problems associated with curved plate and other complex arrangements. Prior art devices have traditionally focused on directing projectiles and large fragments away from persons and property. For example U.S. Pat. No. 3,737,165 to Pencyla (1973), describes a device which is said to employ a series of deflector plates to direct projectiles and fragments rearwardly and downwardly in proximity to a back plate where gravity and any remaining velocity on a vector parallel to the back plate guides them to a collection area. High velocity projectiles impacting the deflector plates at an oblique angle, as described, create a fragmented lead and lead particulate that escape to the surrounding environment, because no means of containment are provided.
As is described in U.S. Pat. No. 3,737,165 to Pencyla (1973), there is a need in the prior art to provide bullet stops which can be arranged in horizontal series, as in a range. A recognized limitation is supporting deflection and containment plates and structure without creating barriers within the zone traveled by projectiles, i.e. vertical support members. For example, the vertical support holding a deflection plate would necessarily be engineered to withstand sustained impact by all classes of projectiles used in the range, as the support is within the zone traveled by those projectiles.
This problem is said to be solved by Pencyla by arranging the bullet stop on a large vertical surface of a wall. This arrangement has the distinct disadvantages of not containing the projectiles after initial impacts. Particulate matter and fragments may freely escape in the opposite direction of the original trajectory after secondary and tertiary impacts. Others have attempted to solve this problem with complex arrangements of curved plate and funnel-type arrangements which, as discussed above, are difficult and costly to manufacture, transport, store, and assemble.
There is thus a need to provide a bullet stop and containment chamber in which bullets are guided to a primary impact which absorbs the bulk of the energy from the bullets, and the impact occurs on a relatively small and readily replaceable component; a bullet stop which is constructed from flat, storable, transportable, and readily constructable stock plate components; which provides a defined containment chamber capable of retaining small projectile fragments and lead particulate; and which can be arranged in horizontal series without vertical support which inhibits the general path of trajectory of the range or which requires engineering to withstand the same.
Those having ordinary skill in the art will appreciate that these and other needs are met by the present invention.